72 For any real square matrix M, let A* (M) be the number of positive eigen values of M counting multiplicities Let A be an 1 xn real symmetric matrix and Q be an nxnreal invertible matrix. Then, (a) Rank A = RankQAQ (b) Rank A RankQAQ () (A)=N* (QAQ) (d) t(A) =(QAO) m to